1. Field of Disclosure
The present disclosure relates to a touch panel. More particularly, the present disclosure relates to an optical-touch panel and a controlling method thereof.
2. Description of Related Art
An optical sensor of an optical-touch system is usually fixed on the upper left corner or the upper right corner around the touch-sensing area. Sometimes, an external force may deform the plane of the touch-sensing area, and it may disposition the optical sensor from its original position related to the touch-sensing area, so that the receiving angle of the optical sensors may be affected accordingly. The disposition of the optical sensor may result in insufficient intensity of the received optical signal, and thereby it will cause noise or misalignment of touch-sensing (such as a discontinuous touch-sensing result while tracking a touch event).
Most of the optical touch modules available in the market utilize an area optical sensor (i.e., a planar-type optical sensor) to overcome aforesaid panel-deformation problem. The area optical sensor is capable of sensing toward different angles with its range of viewable angle. When a deformation occurs to the touch-sensing area, the area optical sensor can reselect an optimal sensing angle other than the current sensing angle. However, the area optical sensor is relatively expensive and complex in the manufacturing process, and also the area optical sensor occupies a larger volume and induces higher power consumption. Moreover, since the area optical sensor requires an extra step for selecting the optimal sensing angle (e.g., selecting different signal wirings corresponding to different sensing angles), the area optical sensor requires more time to capture images.